Convert an Integer to a String

[thoms314159]

I am looking for a way to convert an integer to a string (please note that I mean a variable of type "string", not a C style string). I can currently do it using a couple of ugly lines of codes, but I was wondering if anyone new of a function that would get the job done. If anyone knows of a function that converts a C style string to an actual string, that would be of use too.

Thanks,
Jon

 

[Cagliostro]

I would use ATL:

#include<atlbase.h>
#include<comip.h>
#include<comdef.h>
#include<comutil.h>

int main()
{
_bstr_t x = &quot;number:&quot;;
x += _bstr_t(10);
cout<< (char*)x<< endl;
x += &quot;hello&quot;;
cout<< (char*)x<< endl;
return 0;
}

Ion Filipski

ICQ: 95034075
AIM: IonFilipski
filipski@excite.com

 

[Kalisto]

Have you tried using itoa()?

 

[ArkM]

string s;
int x = ...;
...
{
char junk[16];
s.assign(itoa(x,junk,10));
}

 

[PerFnurt]

>If anyone knows of a function that converts a C style string to an actual string

Simply assign the c-style string to the std::string.

/Per
[sub]
&quot;It was a work of art, flawless, sublime. A triumph equaled only by its monumental failure.&quot;[/sub]

 

[thoms314159]

Thanks all.

 

[ArkM]

After all some syntax sugar:
string& operator << (string& s, int x)
{ // can't redefine string class assign op
char junk[16];
sprintf(junk,&quot;%d&quot;,x); // sprintf - ISO Std, itoa - not
s.append(junk);
return s;
}
...
s << 2003;

 

[chipperMDW]

Complete answer:

Read the FAQ at the C++: UNIX forum.


Short answer:

The most Standard way to do it is with stringstreams. Other ways mentioned, such as itoa and ATL, work, but are non-Standard.

Getting it to a char* through something like sprintf and then converting that to a string is Sandard, of course.

http://www.boost.org

has a lexical_cast &quot;operator&quot; that does this, and will probably be Standard in the near future.

 

[Cagliostro]

>ArkM
is your code more simple than the ATL one:
_bstr_t x = &quot;number:&quot;;
x += _bstr_t(10);
cout<< (char*)x<< endl;//?

Ion Filipski

ICQ: 95034075
AIM: IonFilipski
filipski@excite.com

 

[ArkM]

IonFilipski,
no, my code is not a simplest one.
It's 100% platform-independent (STL only) and 100% Std compl.
I think, it's trivialities, needles to say.
Best Regards!

 

[Cagliostro]

>ArkM
>It's 100% platform-independent
it is 100% while there are only your five lines of code, for teaching purposes. But when you write a real application, it will be at most 5% platform independend [LOL]. So when you use Microsoft C++ you should take all advantages of it. By the way, ATL is also available in BorlandC++ builder and simple BorlandC++.
So in real projects where you need just to implement, you will always forget about platform and compiller independency.

Ion Filipski

ICQ: 95034075
AIM: IonFilipski
filipski@excite.com

 

[ArkM]

IonFilipski,
recently I took part in a real C++ project (XML, JNI, sockets, threads etc, near 100000 source lines) with more than 5% platform-independency (Windows, Solaris, Linux). Platform-dependent code was about 5% or less. That's not a question.
But let's remember our topic. Yes, of course, your sample code above is more better than mine.
Happy weekend!